基于滑模观测器的不确定系统传感器故障重构

Sensor fault reconstruction for a class of uncertain systems based on sliding mode observers

针对一类不确定线性系统,讨论了观测器匹配条件不满足下的传感器故障重构方法.首先,引入增维向量形成观测器匹配条件不满足增维系统,使得增维系统的未知输入包含原系统的未知输入和传感器故障向量;其次,通过构造辅助输出的方法,使得观测器匹配条件满足,然后再利用高阶滑模观测器对辅助输出进行精确估计;第三,基于辅助输出的精确估计,设计鲁棒滑模观测器对系统状态进行估计,在此基础上提出一种传感器故障代数重构方法;最后,通过对一个四阶飞行器模型进行仿真,验证了方法的实用性和有效性.

This paper considers the problem of sensor fault reconstruction for a class of uncertain systems when observer matching conditions are not satisfied. A new augmented system is constructed by introducing a new augmented sate vector. The new augmented system is only with an unknown input vector which consists of the original system＇s unknown input and sensor fault vector. An auxiliary output vector which can satisfy the observer matching condition is proposed, and a high-order sliding mode observer is considered to obtain the exact estimates of the auxiliary outputs. Then, a robust sliding mode observer is developed to asymptotically estimate the system states using the estimated auxiliary outputs. A kind of algebraic reconstruction method of sensor fault is developed. Finally, a numerical simulation example is given to illustrate the effectiveness of the proposed methods.